| 摘要 |
PROBLEM TO BE SOLVED: To protect a motor drive circuit of a direct PWM drive type brushless motor from breakdown due to a reverse regenerative current generated in the motor. SOLUTION: This motor drive device 1 matches operation voltage levels of a direct PWM drive type brushless motor 3, a normal drive type motor 5 with brushes and a normal drive type brushless motor 7 with each other, and a power is supplied through a common motor power supply line L (VM) and a common motor ground line L (M-GND). A reverse regenerative current IMc' generated in the drive circuit 2 of the brushless motor 3 is made to flow into respective drive circuits 4 and 6 of the normal drive type motor 5 with brushes and the normal drive type brushelss motor 7 through the common motor power supply line L (VM) and utilized as parts of the drive currents of the motors. A problem of the motor power supply voltage increase by the reverse regenerative current and that causes the dielectric breakdown of the motor drive circuit can be avoided surely. |
